%%
%% An UIT Edition example
%%
%% Example 09-17-10 on page 191.
%%
%% Copyright (C) 2010 Herbert Voss
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3
%% of this license or (at your option) any later version.
%%
%% See
http://www.latex-project.org/lppl.txt for details.
%%
%%
%% ====
% Show page(s) 1
%%
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{375.57637pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands
\usepackage{mathtools}
\StopShownPreambleCommands
\begin{document}
\[ A = \begin{multlined}[t]
\framebox[3cm]{line 1} \\ \vdots \\ \framebox[3cm]{line n}
\end{multlined} =
B = \begin{multlined}[c]
\framebox[3cm]{line 1} \\ \vdots \\ \framebox[3cm]{line n}
\end{multlined} =
C = \begin{multlined}[b]
\framebox[3cm]{line 1} \\ \vdots \\ \framebox[3cm]{line n}
\end{multlined} =
D \]
\end{document}
